Photochemical switching between colloidal photonic crystals at the nematic-air interface

submitted by: icamvid
Stanislav Chernyshuk, Institute of Physics Abstract: A direct observation of the photochemical switching between colloidal crystals with different lattice constants in a liquid-crystal emulsion is reported. Glycerol droplets introduced in a nematic liquid crystal form two-dimensional hexagonal colloidal crystal at the nematic-air interface with a lattice constant depending on the surface tension LCA. We dope an azobenzene derivative into the LC emulsion to modulate the colloidal structures...

Phase separations in mixtures of a liquid crystal and a colloidal particles

submitted by: icamvid
Akihiko Matsuyama, Kyushu Institute of Technology Abstract: We present a mean field theory to describe phase separations in mixtures of a liquid crystal and a colloidal particle. By taking into account a nematic and a smectic A ordering of liquid crystals and a crystalline ordering of colloidal particles, we calculate the phase diagrams on the temperature-concentration plane. We predict various phase separations, such as a smectic A-crystal phase separation and a smectic A-nematic-crystal...

Colloidal nematostatics

submitted by: icamvid
Victor Pergamenshchik, Institute of Physics Abstract: Colloids interact via the nematic director. As the interaction is of a long range, nematic colloids are much closer to electrostatic systems than to standard colloids in isotropic liquids. I will talk about an elastic "charge" and elastic mutipoles, about their interaction and strange properties, e.g., elastic charge is a vector, elastic dipole can be chiral... and more. Presented at PSSM Workshop on Liquid Crystals and Colloidal...

Simulation studies of spherical nanoparticles in mesogenic media

submitted by: icamvid
Matt Glaser, University of Colorado at Boulder Abstract: We describe results from simulations of spherical nanoparticles in a nematogenic solvent consisting of soft spherocylinders. We find that nanoparticles remain well dispersed in the isotropic (low-density) phase of the solvent, but demix into a nanoparticle-poor nematic phase and a nanoparticle-rich isotropic phase at higher pressures. When the nanoparticle-spherocylinder interactions are modified to promote homeotropic anchoring, the...

Shape Controlled Colloidal Interactions in Anisotropic Fluids

submitted by: icamvid
Clayton Lapointe, University of Colorado at Boulder Abstract: Colloidal particles suspended in nematic liquid crystals are known to exhibit highly directional interactions mediated by the elasticity of the liquid crystal. Using lithographically fabricated platelet colloids having equilateral polygonal shapes, we show that colloids with an even number of sides form elastic quadrupoles whereas those with an odd number of sides form elastic dipoles. These qualitatively different interactions...

Molecular dynamics simulation of liquid crystalline polymers: what can be achieved?

submitted by: icamvid
Jaroslav Ilnytskyi, Institute for Condensed Matter Physics Abstract: Polymeric liquid crystals combine the features of both the polymer and liquid crystal. Their fine-tuning is possible on the stage of synthesis which leads to a number of practical applications (high strength plastics, displays, optical data storage). We present some recent results in molecular dynamics simulations of such systems. Liquid crystalline dendrimer is studied in isotropic, nematic and smectic A solvent and we...

Tunable Cholesteric Liquid Crystal Color

submitted by: icamvid
Liang-Chy Chien, Kent State University Abstract: Cholesteric liquid crystals (CLCs) in the planar texture possess the unique feature of separating incident light into its left- and right-handed circular components by reflecting one component and transmitting the other.1,2 In a planar aligned CLC with a preselected helical pitch only a single wavelength can be Bragg reflected (monochrome). In addition to the temperature dependence of Bragg reflected wavelength of a CLC, there are two ways...

Universal Aspects of Liquid Crystals

submitted by: icamvid
Pavel Pieranski, University of Paris-Sud Abstract: My intention is to focus on a few selected topics that can be interesting also for non specialists. In particular, I would like to say some words about Mark Kac (one the glorious mathematicians from the Lviv School of Mathematics) and the issue of isospectral drum initiated by him. Presented at PSSM Workshop on Liquid Crystals and Colloidal Dispersions http://www.icmp.lviv.ua/statphys2009/pssm/index.html

I-CAMP 2010 Australia Monday July 5 Global Outreach Forum II

submitted by: icamvid

I-CAMP 2010 Australia Monday July 5 Global Outreach Forum II
Parnell Building Rm 222, University of Queensland, Brisbane, Australia
5:30pm Monday July 5, 2010